Supporting plate, stage device, exposure apparatus, and exposure method

ABSTRACT

For example, to control an effect due to entrance and leakage of liquid for exposure and allow a preferable exposure processing, a support surface is provided which supports an object. The support surface is liquid repellant, and a collection device is provided which collects liquid from the support surface.

INCORPORATION BY REFERENCE

The disclosure of the following priority application is hereinincorporated by reference in its entirety: Japanese Patent ApplicationNo. 2003-373084 filed Oct. 31, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a supporting plate, a stage device, anexposure device, and an exposure method, and particularly to asupporting plate which is advantageously used with respect to asubstrate on a stage, a stage device, an exposure apparatus, and anexposure method, at the time of exposure via a projection optical systemthat utilizes a liquid immersion technique.

2. Description of Related Art

A semiconductor device and a liquid crystal display device aremanufactured by a so-called photolithographic method which transfers apattern formed on a mask onto a photosensitive substrate. An exposureapparatus which is used in this photolithographic method is providedwith a mask stage which supports a mask, and a substrate stage whichsupports a substrate. The exposure apparatus transfers a mask patternonto a substrate via a projection optical system while successivelymoving the mask stage and the substrate stage. Recently, higherresolution of the projection optical system corresponding to higherintegration of a device pattern is demanded. The resolution of theprojection optical system increases as an exposure wavelength which isused becomes shorter and a numerical aperture of the projection opticalsystem becomes larger. Because of this, the exposure wavelength which isused in exposure apparatus has become shortened over the years, and thenumerical aperture of projection optical systems has increased.Furthermore, an exposure wavelength of 248 nm of a KrF excimer laser iscurrently the mainstream, but an exposure wavelength of 139 nm of an ArFexcimer laser also has been put into practice. In addition, in the caseof performing exposure, a depth of focus (DOF) also becomes important aswell as the resolution. The resolution R and the depth of focus δ can beexpressed by the following equations.R=k1·λ/NA  (1)δ=±k2·λ/NA ²  (2)

Here, λ is an exposure wavelength, NA is a numerical aperture of theprojection optical system, and k1, k2 are process coefficients.According to equations (1) and (2), in order to increase the resolutionR, by shortening the exposure wavelength λ and increasing the numericalaperture NA, it is understood that the depth of focus δ becomesnarrower.

When the depth of focus δ becomes too narrow, it is difficult to match asubstrate surface with an image plane of the projection optical system,and there is a possibility that a focus margin may become insufficientat the time of an exposure operation. Therefore, a liquid immersionmethod has been proposed, as disclosed in, e.g., WO99/49504, as a methodwhich substantially shortens an exposure wavelength and broadens thedepth of focus. This liquid immersion method forms a liquid immersionarea by filling the space between a lower surface of the projectionoptical system and a substrate surface with liquid such as water, anorganic solvent, or the like, and improves the resolution by takingadvantage of the fact that the wavelength of the exposure light inliquid becomes 1/n (n is normally approximately 1.2 through 1.6depending on the index of refraction of the liquid) as compared to thewavelength in air, and increases the depth of focus by approximatelyn-times.

SUMMARY OF THE INVENTION

The following problems exist in the above-mentioned apparatus thatutilizes liquid immersion.

In the above-mentioned exposure apparatus, exposure is performed in astate in which liquid is filled between a projection optical system anda wafer, so there are cases in which liquid may be splashed to locationsexternal of the wafer if an unexpected operation is performed due toerrors when a stage moves.

For example, in the exposure apparatus described in WO99/49504, liquidis supplied between a projection optical system and a wafer by a liquidsupply mechanism, and the supplied liquid is collected from the spacebetween the wafer and the projection optical system by a liquidcollection mechanism using vacuum suction or the like. However, once theoperation of the liquid collection mechanism stops in a state in whichthe liquid supply mechanism is still operated, there is a possibilitythat the liquid on the wafer may increase and be splashed at theperiphery.

Because of this, in a liquid immersion exposure apparatus, there is apossibility that problems may occur such as device/member failure,leaking, rust/oxidation, etc. due to splashed liquid. Furthermore, inthis case, there also is a problem that exposure processing cannot beperformed well.

It is a first object of this invention to provide a supporting platewhich suppresses an effect due to leakage and entrance of exposureliquid, and which enables a good exposure processing, and to a stagedevice, an exposure apparatus, and an exposure method using thatsupporting plate.

In order to accomplish the above-mentioned object, the followingstructure can be used. A supporting plate according to one embodiment ofthis invention includes a support surface which supports an object, andthe supporting plate is made to be liquid repellent. In addition, acollection device is arranged to collect liquid from the supportingplate.

In the supporting plate of this embodiment of the invention, even whenthe liquid is splashed or discharged to the supporting plate, thisliquid can be collected by the collection device. Therefore, it ispossible to suppress problems such as device/member failure, leaking,rust/oxidation, etc., or to reduce the effects of such problems. Inaddition, with this embodiment of the invention, the supporting plate isliquid repellent, so the splashed or discharged liquid cannot be spreadover the support surface, and can easily move off the plate. Thus, acollection operation can be performed easily.

A stage device according to one embodiment of this invention is providedwith a movable body which holds a substrate, and in which liquid issupplied to a surface of the substrate, and a supporting plate whichmovably supports the movable body. When liquid is discharged to thesupporting plate, a collection device is arranged which collects thedischarged liquid.

Therefore, in the stage device of this embodiment of the invention, evenwhen liquid is splashed or discharged to the supporting plate from thesurface of the substrate when the movable body moves or the like, theliquid can be collected by the collection device, so it is possible tosuppress problems such as a device/member failure, leakage,rust/oxidation, etc., or to reduce the effects of such problems.

An exposure apparatus according to one embodiment of this inventionexposes a pattern of a mask onto a photosensitive substrate which isheld to a substrate stage via a projection optical system. The stagedevice described above is used as a substrate stage, and a pattern imageis projected onto the photosensitive substrate via liquid which isfilled between an end portion of the projection optical system and thephotosensitive substrate.

An exposure method of one embodiment of this invention, in which apattern of a mask is exposed to a substrate on a substrate stage, whichis movably supported on a supporting plate, by a projection opticalsystem includes a step of filling between an end portion of a projectionoptical system and the substrate with liquid, and a step of collectingthe discharged liquid when the liquid is discharged to the supportingplate.

Thus, according to exposure apparatus and exposure methods of someembodiments of this invention, even when the liquid which is filledbetween the end portion of the projection optical system and thephotosensitive substrate is splashed/discharged to the supporting plate,this liquid can be collected by the collection device. Thus, it ispossible to suppress problems such as a device/member failure, leakage,rust/oxidation, etc., or to at least reduce the effects of suchproblems.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in conjunction with the followingdrawings in which like reference numerals designate like elements, andin which:

FIG. 1 is a schematic structure diagram showing a supporting plate and astage device of a first embodiment of this invention;

FIG. 2 is a perspective view showing a stage device;

FIG. 3 is an outer perspective view showing an X guide stage and asubstrate supporting plate within the stage device;

FIG. 4 is a perspective view showing a schematic structure of asupporting plate and a stage device according to a second embodiment ofthis invention;

FIG. 5 is a perspective view showing a schematic structure of asupporting plate and a stage device according to a third embodiment ofthis invention;

FIG. 6 is a schematic structure diagram showing an exposure deviceutilizing an embodiment of this invention;

FIG. 7 is a schematic structural diagram showing the vicinity of an endportion of a projection optical system, a liquid supply mechanism, and aliquid collection mechanism;

FIG. 8 is a plan view showing a positional relationship among aprojection area of the projection optical system, the liquid supplymechanism, and the liquid collection mechanism;

FIG. 9 is a diagram showing another embodiment of a collection portionarranged on the substrate supporting plate;

FIG. 10 is a diagram showing another embodiment of the collectionportion arranged on the substrate supporting plate;

FIG. 11 is a perspective view showing another embodiment of the X guidestage; and

FIG. 12 is a flowchart showing an example of a manufacturing process ofa semiconductor device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following explains some examples of a supporting plate, a stagedevice, an exposure apparatus, and an exposure method which utilizeaspects of this invention.

A first embodiment explains a supporting plate according to some aspectsof this invention, and a stage device provided with this supportingplate. FIG. 1 is a schematic structural diagram showing an embodiment ofa stage device utilizing some aspects of this invention.

A stage device ST shown in FIG. 1 is mainly constituted by a substratesupporting plate (supporting plate) 41 which is supported by three orfour points on a base plate 4 via a vibration isolation unit (removaldevice) 9, a substrate stage PST as an object (movable body) whichsupports the substrate P and moves a top surface (support surface) 41Aof the substrate supporting plate 41, an X linear motor 47 which drivesthe substrate stage PST in an X axis direction (horizontal direction inFIG. 1), and a Y linear motor 48 which drives the substrate stage PST ina Y axis direction (direction perpendicular to a paper plane of FIG. 1).The vibration isolation unit 9 is provided with an actuator such as anair mount, a voice coil motor, or the like in which an internal pressurecan be controlled, and is constituted such that the substrate supportingplate 41 is driven in a direction perpendicular to the top surface 41Aby driving the actuator.

The substrate stage PST is constituted by a table portion PH whichadsorbs (by suction) and holds the substrate P, and a stage portion PSwhich is movably arranged along with table portion PH. In addition, airbearings 42, which are formed of a plurality of non-contact bearings,are arranged under the stage portion PS. The air bearings 42 areprovided with exit ports 42B which discharge air to the top surface(guide surface) 41A of the substrate supporting plate 41, and intakeports 42A which adsorb air between the lower surface (bearing surface)of the substrate stage PST and the guide surface 41A. Due to the balancebetween the pressing force of the outflow of air from the exit ports 42Band an adsorption force by the intake ports 42A, a predetermined spaceis maintained between the lower surface of the substrate stage PST(stage portion PS) and the guide surface 41A. That is, the substratestage PST is supported in a non-contact manner by the air bearings 42with respect to the top surface (guide surface) 41A of the substratesupporting plate 41, and is two-dimensionally movable within a planeparallel to the top surface 41A, i.e., within an XY plane, and ismicro-rotatable in a θZ direction of rotation about an axis parallel toa Z axis, which is perpendicular to the top surface 41A. Furthermore,the table portion PH is movably arranged in the Z axis direction, θXdirection (direction of rotation about an axis parallel to the X axis),and θY direction (direction of rotation about an axis parallel to the Yaxis). The substrate stage drive mechanism is controlled by a controldevice CONT. That is, the table portion PH controls a Z position and aninclination angle of the substrate P, matches the surface of thesubstrate P with a predetermined plane position, and positions thesubstrate P in the X axis direction and Y axis direction.

Furthermore, spray ports (second removal devices) 75 which spray air arearranged in the vicinity of the bottom portion of the stage portion PS.The spray ports 75 spray air, which removes any liquid remaining on thetop surface 41A of the substrate supporting plate 41, in a diagonallydownward direction toward the top surface 41A. A plurality of sprayports are formed in the four corners of the periphery of the stageportion PS (see FIG. 2; however, in FIG. 2, spray ports that are formedon the +X side and +Y side of the stage portion PS are not depicted),and are connected to an undepicted air supply source.

Moving mirrors 45 are arranged on the substrate stage PST (i.e., on asurface 62 of the table portion PH). Furthermore, laser interferometers46 are arranged at positions opposite to the moving mirrors 45. Theposition of the substrate P on the substrate stage PST in thetwo-dimensional directions X and Y, and the rotation angle are measuredby the laser interferometers 46 in real time, and the measurementresults are provided to the control device CONT. The control device CONTpositions the substrate P, which is supported on the substrate stagePST, by driving a substrate stage drive mechanism including a linearmotor based on the measurement result of the laser interferometers 46.Additionally, the moving mirrors 45 can be arranged on the side surfacesof the substrate stage PST, and the table portion PH can be made to beentirely flat.

Also arranged on the substrate stage PST (table portion PH) in thevicinity of the substrate P are a supply nozzle 14 which supplies liquid1 to the substrate P, and a collection nozzle 21 which collects theliquid 1 on the substrate P.

FIG. 2 is a schematic perspective view showing the substrate stage PSTand the substrate stage drive mechanism which drives the substrate stagePST. In FIG. 2, the substrate stage PST (stage portion PS) is movablysupported by an X guide stage 44 in the X axis direction. The substratestage PST can be moved by an X linear motor 47 in the X axis directionby a predetermined stroke, while being guided with the X guide stage 44.The X linear motor 47 is provided with a stator 47A which is arranged soas to extend on the X guide stage 44 in the X axis direction, and amovable portion 47B which is fixed to the substrate stage PST andarranged in correspondence with the stator 47A. Furthermore, the movableportion 47B is driven with respect to the stator 47A, so the substratestage PST is moved in the X axis direction. Here, the substrate stagePST is supported in a non-contact manner by a magnetic guide formed of amagnet and an actuator, which maintains a predetermined gap in the Zaxis direction with respect to the X guide stage 44. The substrate stagePST is moved by the X linear motor 47 in the X axis direction in a statein which the substrate stage PST is supported in a non-contact manner onthe X guide stage 44. Furthermore, this is not depicted, but byarranging an encoder scale on the X guide stage 44 and measuring theencoder scale in the substrate stage PST, an encoder (encoder head) isprovided which measures the relative positional relationship between theX guide stage 44 and the substrate stage PST.

FIG. 3 is a diagram showing only the X guide stage 44 and the substratesupporting plate 41 of the stage device ST shown in FIG. 2.

As shown in FIG. 3, the X guide stage 44 which is a stage structuralbody and arranged above the substrate supporting plate 41 is formed in across-sectional substantially concave shape which is opened upwardly. Onthe top surface, inclined surfaces (second inclined portion) 44A areformed which are inclined gradually downward to the substantiallycentral portion in the width direction. In addition, at the low endportion (the lowest portion) of the inclined surfaces 44A, a pluralityof drain ports (through holes) 44B are formed, spaced apart from eachother in a longitudinal direction of the X guide stage 44. The drainports 44B are formed so as to be positioned above the top surfaces 41Aof the substrate supporting plate 41, i.e., at positions such that whenliquid is discharged from the drain ports 44B, the liquid drips onto thetop surfaces 41A.

In addition, the stator 47A of the X linear motor 47 and the inclinedsurfaces 44A (i.e., the concave portion of the X guide stage 44) arespaced apart from each other by using an undepicted spacer locatedwithin a concave portion of the X guide stage 44, so as to not preventliquid from moving along the inclined surfaces 44A.

Additionally, the stage device ST includes a collection device 71 thatcollects liquid discharged to the substrate supporting plate 41. Thecollection device 71 is constituted by a gutter (collection portion) 72which is arranged along the outer circumference of the substratesupporting plate 41, a waste liquid tube 73 which is connected to thegutter 72, and a suction device 74 which suctions the liquid dischargedto the gutter 72 via the waste liquid tube 73.

The gutter 72 is formed in a cross-sectional substantially U shape(concave shape), which is opened upwardly (see FIG. 1), and liquidrepellent coating (liquid repellent processing) of a fluorine orfluorine compound is performed on the bottom surface 72A and the sidesurface 72B within the concave portion. In addition, the bottom surface72A of the gutter 72 is arranged at a position lower than the topsurface 41A of the supporting plate 41. A corner portion C1 (corner ofthe +X and −Y sides) connected to the waste liquid tube 73 is made to bethe lowest portion, and a corner portion C2 opposite to the cornerportion C1 is made to be the highest position. This forms inclinedportions, which are inclined in both the X axis direction and the Y axisdirection.

Additionally, on the top surface 41A of the substrate supporting plate41 as well, in the same manner as the gutter 72, liquid repellentcoating formed of fluorine or fluorine compound is performed, and thusliquid repellency is provided.

Furthermore, liquid repellent coating for the substrate supporting plate41 can be performed for the entire substrate supporting plate 41, notonly for the top surface 41A.

Meanwhile, on both ends in the longitudinal direction of the X guidestage 44, a pair of Y linear motors 48, 48 are arranged which can movethe X guide stage 44 with the substrate stage PST in the Y axisdirection. The respective Y linear motors 48, 48 are provided withmovable parts 48B which are arranged on both ends, in the longitudinaldirection, of the X guide stage 44, and stators 48A which are arrangedin correspondence with the movable parts 48B. Furthermore, as themovable parts 48B are driven by the stators 48A, the X guide stage 44 ismoved in the Y axis direction along with the substrate stage PST.Furthermore, by adjusting the respective drives of the Y linear motors48, 48, the X guide stage 44 can be rotatably moved in the θZ direction.Therefore, the substrate stage PST can be moved by the Y linear motors48, 48 in the Y axis direction and in the θZ direction substantiallyintegrally with the X guide stage 44.

On both sides of the X axis direction of the substrate supporting plate41, guide portions 49 are arranged which are formed in an L shape asseen from a front view and guide the movement of the X guide stage 44 inthe Y axis direction. In this embodiment, stators 48A of the Y linearmotors 48 are arranged on the flat portions 49B of the guide portions49. Meanwhile, U-shaped guide members 50 are respectively arranged onboth end portions in the longitudinal direction under the X guide stage44. The guide portions 49 are engaged to the guide members 50 andarranged so that the top surfaces (guide surfaces) 49A of the guideportions 49 face the internal surfaces of the guide members 50. Airbearings 51 which are non-contact bearings are arranged on the guidesurfaces 49A of the guide portions 49, and the X guide stage 44 issupported in a non-contact manner with respect to the guide surfaces49A.

Additionally, air bearings 52 which are non-contact bearings existrespectively between the stators 48A of the Y linear motors 48 and theflat portions 49B of the guide portions 49, and the stators 48A aresupported in a non-contact manner with respect to the flat portions 49Bof the guide portions 49 by the air bearings 52. Because of this, due tothe conservation of momentum, according to the movement in the +Ydirection (or −Y direction) of the X guide stage 44 and the substratestage PST, the stators 48A are moved in the −Y direction (or +Ydirection). Due to the movement of the stators 48A, a reaction forcecaused due to the movement of the X guide stage 44 and the substratestage PST is canceled, and changes in a centroid position can beavoided. That is, the stators 48A function as a so-called countermass.

In the above-mentioned structured stage device ST, by controlling asupply amount of the liquid 1 from the supply nozzle 14 and a collectionamount of the liquid 1 by the collection nozzle 21, in a condition inwhich a predetermined amount of liquid 1 is maintained on the surface ofthe substrate P, the substrate stage PST can be moved by the substratestage drive mechanism along the supporting plate 41.

Here, due to reasons such as the occurrence of a problem in liquidcollection by the collection nozzle 21, etc., when liquid is splashed ordischarged from the substrate, part of the liquid drips (or spills) ontothe X guide stage 44, and another part drips (or spills) onto the topsurface 41A of the substrate supporting plate 41.

The liquid discharged to the X guide stage 44 flows along the inclinedsurfaces 44A without remaining within the concave portion, and dripsonto the top surface 41A of the substrate supporting plate 41 via thedrain ports 44B at the lower end portion of the inclined surfaces 44A(see FIG. 3).

Here, when the substrate stage PST is operated, air is sprayed out fromthe spray ports 75, arranged in the bottom portion of the substratestage PST (stage portion PS), to the top surface 41A. The top surface41A of the supporting plate 41 is provided with liquid repellency. Thus,the liquid discharged to the top surface 41A is moved as liquid dropsand is collected by the gutter 72. Furthermore, in the gutter 72 aswell, liquid repellent processing is performed, and the bottom surface72A is inclined, so liquid is discharged (rolls) below the top surface41A (i.e., below the surface of the substrate P) along the bottomsurface 72A in a liquid drop state, and is discharged and collected fromthe waste liquid tube 73 through suction by the suction device 74.

Meanwhile, when the operation of the substrate stage PST is stopped, forexample, due to an error, there is a possibility that liquid which is ata position in which air is not supplied from the spray ports 75 mayremain on the substrate supporting plate 41. In this case, by drivingactuators (e.g., linear motors, voice coil motors, etc.) of thevibration isolation units 9, the top surface 41A of the substratesupporting plate 41 is inclined with respect to a horizontal plane. Bydoing this, liquid drops roll over the top surface 41A and fall into thegutter 72. At this time, regardless of the direction of inclination ofthe substrate supporting plate 41, the bottom surface 72A of the gutter72 is inclined. Thus, the liquid can be collected via the waste liquidtube 73, but by making the supporting plate 41 inclined at a position inwhich the corner portion C1 connected to the waste liquid tube 73 is thelowest, the liquid drops are discharged to the gutter 72 in the vicinityof the corner portion C1, so the time until the liquid on the supportingplate 41 is discharged via the waste liquid tube 73 can be shortened,which is preferable.

Thus, in this embodiment, even when the liquid supplied onto thesubstrate P is splashed and discharged to the substrate supporting plate41 for some reason, this liquid can be collected by the collectiondevice 71, so problems due to the splashed and discharged liquid, suchas device/member failure, leaking, rust/oxidation, etc., can be avoided.Additionally, in this embodiment, the bottom portion 72A of the gutter72 of the collection device 71 has liquid repellency, and an inclinedsurface is provided which discharges the liquid below the supportingplate top surface 41A, so discharging and collection can be smoothlyperformed without clogging the liquid in the gutter 72. In addition, inthis embodiment, liquid repellency is provided on the top surface 41A ofthe substrate supporting plate 41, so the liquid cannot be easilyattached to the surface, but rather can be easily dripped into thegutter 72. Additionally, in this embodiment, air is sprayed from thespray ports 75 to the supporting plate top surface 41A, so the liquidwhich remains on the surface can be easily removed, and even when theliquid is splashed onto the supporting plate top surface 41A during thedrive of the substrate stage PST, the possibility of liquid being caughtbetween the air bearings 42 and the top surface 41A can be reduced, andthis can contribute to the stable drive of the substrate stage PST.Furthermore, in this embodiment, even when the liquid cannot be removedwith air spray, the liquid can be easily removed by inclining thesubstrate supporting plate 41 by the vibration isolation units 9.

Furthermore, in the embodiment which was thus described, the liquidwhich has been discharged can be collected by the substrate supportingplate 41, so a structure is provided in which the liquid supplied ontothe surface of the substrate P does not collect on the substrate stagePST. In this case, vibration due to the liquid collection can becontrolled, and by covering a large part of the substrate surface byliquid, the temperature deterioration of the substrate due to air heatcan be controlled.

Additionally, in this embodiment, in the X guide stage 44 as well, thesplashed/discharged liquid can be guided downwardly by the inclinedsurfaces 44A and discharged from the drain ports 44B, so a heat effectdue to the liquid remaining on the X guide stage 44 can be suppressed,and it is possible to suppress liquid from generating water stains andbacteria, as water tends to do. In addition, in the X guide stage 44 aswell, in the same manner as the supporting plate top surface 41A and thebottom surface 72A of the gutter 72, it is preferable that liquidmovement can be easily facilitated by applying liquid repellency.Furthermore, it is preferable that an encoder head or the like arrangedon the substrate stage PST should be covered by a cover or the like soas to not contact the liquid.

Next, a second embodiment of a supporting plate and stage deviceutilizing aspects of this invention is explained. FIG. 4 is a diagramschematically showing the substrate stage PST, the substrate supportingplate 41, and the X guide stage 44 within the stage device. Furthermore,in FIG. 4, the moving mirror and the substrate on the substrate stagePST, and the gutter of the substrate supporting plate 41 are omittedfrom the drawing, although they would be present in the actual device.

In this embodiment, as shown in FIG. 4, on the top surface of the tableportion PH of the substrate stage PST, a groove portion 76 is formedalong an edge (outer circumference). Furthermore, on one side surface ofthe table portion PH, a slot portion 77 is formed which is positionedabove a concave portion 44C of the X guide stage 44, and extends in theZ axis direction, and is connected to the groove portion 76.

Furthermore, in the concave portion 44C of the X guide stage 44, a drainport 44B is formed at a position displaced in an outward direction fromthe substrate supporting plate 41 in the X direction. A waste liquidtube 78 is connected to the waste drain port 44B. Additionally, asuction device 79 which suctions liquid via the waste liquid tube 78 isconnected to the waste liquid tube 78. Furthermore, in the X guide stage44, the bottom portion 44D within the concave portion 44C is formed soas to be inclined so that the drain port 44B is located at the lowestpart.

In the above-mentioned structure, the liquid applied onto the tableportion PH is discharged to the groove portion 76 and then to theconcave portion 44C of the X guide stage 44 via the slot portion 77.Furthermore, the liquid discharged to the concave portion 44C isdischarged to the drain port 44B along the incline of the bottom portion44D, and is discharged and collected from the waste liquid tube 78 dueto the suction of the suction device 79.

Thus, in this embodiment, the liquid splashed and discharged to theconcave portion 44C of the X guide stage 44 does not reach the topsurface 41A of the substrate supporting plate 41, so it is possible toreduce the liquid amount which remains on the top surface 41A.Additionally, a possibility of liquid being caught between the airbearings and the top surface 41A can be further reduced. Therefore, thedrive stability of the substrate stage PST can be further improved.

Next, a third embodiment of a supporting plate and stage deviceutilizing aspects of this invention is explained. The only differencebetween the third and second embodiments is the structure whichdischarges liquid from the drain port 44B. That is, in this embodiment,the drain port 44B of the X guide stage 44 is formed above the gutter72. Furthermore, a waste liquid tube or the like is not connected to thedrain port 44B.

In the above-mentioned structure, the liquid discharged to the concaveportion 44C of the X guide stage 44 flows along the incline of thebottom portion 44D, and is collected by the gutter 72 as it naturallydrips from the drain port 44B. Thus, in this embodiment, the liquidsplashed and discharged to the X guide stage 44 is not forciblyadsorbed, so generation of vibration due to suction can be suppressed.

Next, an exposure apparatus provided with the stage device ST shown inthe above-mentioned first embodiment is explained with reference toFIGS. 6-8. In this embodiment, in an exposure apparatus which projectsand exposes a pattern image of a mask onto a photosensitive substrate,an example is used in which a stage device of the above-mentionedembodiment is applied to a substrate stage which holds and moves aphotosensitive substrate. Additionally, in this embodiment, the samesymbols as in the above-mentioned first embodiment are used for the samestructural elements, and their explanation is omitted or simplified.

FIG. 6 is a schematic structural diagram showing an exposure apparatusutilizing aspects of this invention.

In FIG. 6, an exposure apparatus EX is equipped with a mask stage MSTthat supports a mask M, a stage device ST shown in FIGS. 1-3 having asubstrate stage PST that supports a substrate (photosensitive substrate)P, an illumination optical system IL that illuminates with exposurelight EL the mask M supported by the mask stage MST, a projectionoptical system PL that projects and exposes a pattern image of the maskilluminated by the exposure light EL onto the substrate P supported bythe substrate stage PST, and a control device CONT that generallycontrols the operation of the entire exposure apparatus EX. To thecontrol device CONT, a warning device K that generates warnings whenabnormalities occur in the exposure process is connected. In addition,the exposure apparatus EX is equipped with a main column 3 that supportsthe mask stage MST and the projection optical system PL. The main column3 is placed on a base plate 4 mounted horizontally to the floor. Anupper side step portion 3A and a lower side step portion 3B that projectinwardly are formed on the main column 3.

The exposure apparatus EX of this embodiment is an immersion exposureapparatus, in which an immersion method is used to substantially widenthe depth of focus as well as increase the resolution by substantiallyshortening the exposure wavelength, and which is equipped with a fluidsupply mechanism 10 that supplies fluid 1 onto the substrate P and afluid collecting mechanism 20 that collects the fluid 1 from thesubstrate P. The exposure apparatus EX forms an immersion region AR2 ata part of the substrate P including a projection region AR1 of theprojection optical system PL by the fluid 1 supplied from the fluidsupply mechanism 10. In detail, the exposure apparatus EX fills thefluid 1 between an optical element 2 located at a front end portion(lower end portion) of the projection optical system PL and a surface ofthe substrate P, and exposes the substrate P by projecting a patternimage of the mask M onto the substrate P through the fluid between theprojection optical system PL and the substrate P.

In this embodiment, the explanation is made with an example using ascanning-type exposure apparatus (a so-called scanning stepper), as theexposure apparatus EX, that exposes a pattern formed on the mask M ontothe substrate P while synchronously moving the mask M and substrate P inmutually different directions (opposite directions) in the scanningdirection. In the below description, the direction that matches anoptical axis AX of the projection optical system PL is designated as aZ-axis direction, a direction (scan direction) of the synchronousmovement by the mask M and the substrate P in a plane perpendicular tothe Z-axis direction is designated as an X-axis direction, and thedirection (non-scan direction) perpendicular to the Z-axis direction andthe X-axis direction is designated as a Y-axis direction.

The term “substrate” includes a substrate on which a photoresist, whichis a photosensitive material, is applied on a semiconductor wafer, andthe term “mask” includes a reticle on which a device pattern to bereduced and projected on the substrate is formed.

The illumination optical system IL is supported by a support column 5fixed on the upper part of the main column 3. The illumination opticalsystem IL illuminates the mask M supported by the mask stage MST withthe exposure light EL, and has an exposure light source, an opticalintegrator that uniformizes the intensity of the luminous flux ejectedfrom the exposure light source, a condenser lens that collects theexposure light EL from the optical integrator, a relay lens system, anda variable field stop that sets an illumination region on the mask M bythe exposure light EL in a slit shape. The predetermined illuminationregion on the mask M is illuminated with the exposure light EL having auniform intensity distribution by the illumination optical system IL. Asthe exposure light EL ejected from the illumination optical system ILmay be a bright line in the ultraviolet region (g-line, h-line, ori-line) ejected from a mercury lamp, ultraviolet light (DUV light), suchas KrF excimer laser light (wavelength: 248 nm), and vacuum ultravioletlight (VUV light), such as ArF excimer laser light (wavelength: 193 nm)and F₂ laser light (wavelength: 157 nm). In this embodiment, the ArFexcimer laser light is used.

In this embodiment, pure water is used as the fluid 1. The pure water istransmissive to the bright line in the ultraviolet region (g-line,h-line, or i-line) ejected from the mercury lamp, for example, and thefar ultraviolet light (DUV light), such as the KrF excimer layer light(wavelength: 248 nm).

The mask stage MST supports the mask M and is equipped with an opening34A for passing the pattern image of the mask M in the center partthereof On the upper side step portion 3A of the main column 3, a masksupport plate 31 is supported via a vibration isolation unit 6. Anopening 34B for passing the pattern image of the mask M is also formedin the center part of the mask support plate 31. A plurality of airbearings 32, which are non-contact bearings, are provided on the lowersurface of the mask stage MST. The mask stage MST is supported on theupper surface (guide surface) 31A of the mask support plate 31 by theair bearing 32 without contact, and is movable two-dimensionally in theplane perpendicular to the optical axis AX of the projection opticalsystem PL, that is, the XY plane, and minutely rotatable in the θZdirection, by the mask stage drive mechanism, such as a linear motor. Amovable mirror 35 is provided on the mask stage MST. A laserinterferometer 36 is provided at a position facing the movable mirror35. The position in a two-dimensional direction and a rotational anglein the θZ direction (including rotational angles in the θX and θYdirections depending on the case) of the mask M on the mask stage MSTare calculated in real time by the laser interferometer 36, and theresult of such measurements is output to the control device CONT. Thecontrol device CONT controls the position of the mask M supported by themask stage MST by driving the mask stage drive mechanism based on theresult of measurement by the laser interferometer 36.

The projection optical system PL projects and exposes the pattern of themask M onto the substrate P at a predetermined projection magnificationβ, and consists of a plurality of optical elements including an opticalelement (lens) 2 provided at the front end portion on the substrate Pside. These optical elements are supported by a lens barrel PK. In thisembodiment, the projection optical system PL is a reduction system, inwhich the projection magnifications β is ¼ or 1/5, for example. Theprojection optical system PL may be an equal magnification system or anenlargement system. An outer circumferential portion of the lens barrelPK is provided with a flange portion FLG. In addition, on the lower sidestep 3B of the main column 3, a lens barrel support plate 8 is supportedvia a vibration isolation unit 7. By engaging the flange portion FLG ofthe projection optical system PL with the lens barrel support plate, theprojection optical system PL is supported to the lens barrel supportplate 8.

The optical element 2 at the front end portion of the projection opticalsystem PL of this embodiment is provided attachably and detachably(replaceably) to the lens barrel PK. The fluid 1 in the immersion regionAR2 contacts the optical element 2. The optical element 2 is formed byfluorite. Because the fluorite has high attractiveness with water, thefluid 1 can be adhered substantially to the entire surface of the fluidcontact surface 2 a of the optical element 2. In other words, becausethe fluid (water) 1 having high adherence with the fluid contact surface2 a of the optical element 2 is supplied in this embodiment, theadherence between the fluid contact surface 2 a of the optical element 2and the fluid 1 is high. Therefore, an optical path between the opticalelement 2 and the substrate P can be accurately filled with the fluid 1.In addition, the optical element 2 may be quartz having highattractiveness with water. Moreover, by performing a hydrophilization(lyophilization) process to surface 2 a, the attractiveness with thefluid 1 can be increased.

A plate member 2P is provided so as to surround the optical element 2. Asurface (i.e., lower surface) that faces the substrate P of the platemember 2P is a flat surface. The lower surface (fluid contact surface) 2a of the optical element 2 also is a flat surface, and the lower surfaceof the plate member 2P and the lower surface of the optical element 2are substantially flat. As a result, the immersion region AR2 can bewell formed in a wide range. In addition, the lower surface of the platemember 2P can be processed with a surface treatment (hydrophilictreatment) similarly to the optical element 2.

FIG. 7 is an enlarged diagram showing the vicinity of the fluid supplymechanism 10, fluid collecting mechanism 20, and the front portion ofthe projection optical system PL. The fluid supply mechanism 10 suppliesthe fluid 1 between the projection optical system PL and the substrateP, and is equipped with a fluid supply portion 11 that can eject thefluid 1, and a supply nozzle 14 that is connected to the fluid supplyportion 11 via a supply tube 15 and supplies the fluid ejected from thefluid supply portion 11 onto the substrate P. The supply nozzle 14 ispositioned near the surface of the substrate P. The fluid supply portion11 is equipped with a tank for accommodating the fluid 1, a pressurepump, and the like. The fluid 1 is supplied onto the substrate P throughthe supply tube 15 and the supply nozzle 14. The fluid supply operationof the fluid supply portion 11 is controlled by the control device CONT,and the control device CONT can control the amount of fluid supplied perunit time to the substrate P by the fluid supply portion 11.

In the middle of the supply tube 15, a flow meter 12 for measuring theamount of the fluid 1 supplied to the substrate P by the fluid supplyportion 11 (amount of fluid supplied per unit time) is provided. Theflow meter 12 constantly monitors the amount of fluid 1 to be suppliedon the substrate P and outputs the result of the measurement to thecontrol device CONT. In addition, a valve 13 for opening and closing aflow path of the supply tube 15 is provided in the supply tube 15between the flow meter 12 and the supply nozzle 14. The open/closeoperation of the valve 13 is controlled by the control device CONT. Inaddition, the valve 13 according to this embodiment is of a so-callednormal-off type that mechanically closes the flow path of the supplytube 15 when a drive source (power source) of the exposure apparatus EX(control device CONT) is stopped due to, for example, power outage orthe like.

The fluid collecting mechanism 20 collects the fluid on the substrate Psupplied by the fluid supply mechanism 10 and includes a collectingnozzle (absorption opening) 21 positioned near the surface of thesubstrate P, and a vacuum system 25 connected to the collecting nozzle21 via a collecting tube 24. The vacuum system 25 is structured byincluding a vacuum source, and its operation is controlled by thecontrol device CONT. By driving the vacuum system 25, the fluid 1 on thesubstrate P is collected through the collecting nozzle 21 along with theambient gas (air). In addition, as the vacuum system 25, a vacuum systemfor a factory, in which the exposure apparatus EX is located, may beused without providing a separate vacuum pump on the exposure apparatus.

A gas/fluid separator 22 that separates the fluid 1 and the gas absorbedby the collecting nozzle 21 is provided in the middle of the collectingtube 24. As described above, the fluid 1 on the substrate P and theambient gas are collected by the collecting nozzle 21. The gas/fluidseparator 22 separates the fluid 1 and the gas collected by thecollecting nozzle 21. For the gas/fluid separator 22, a gravityseparation method that separates the fluid and the gas by dropping thefluid using gravity through a hole portion, or a centrifugal separationmethod that separates the collected fluid and gas using centrifugalforce, may be used. The vacuum system 25 absorbs the gas separated bythe gas/fluid separator 22.

A dryer 23 that dries the gas separated by the gas/fluid separator 22 isprovided in the collecting tube 24 between the vacuum system 25 and thegas/fluid separator 22. If a fluid composition is mixed in the gasseparated by the gas/fluid separator 22, by drying the gas using thedryer 23 and by flowing the dried gas into the vacuum system 25,occurrence of troubles, such as malfunction of the vacuum system 25,originated from the fluid composition that is flowed thereinto, can beprevented. For the dryer 23, a method for removing the fluid compositionby cooling the gas supplied by the gas/fluid separator 22 (gas in whichthe fluid composition is mixed) below the dew point of the fluid or amethod for removing the fluid composition by heating the gas above theboiling point of the fluid, may be used.

On the other hand, the fluid 1 that has been separated by the gas/fluidseparator 22 is collected in a fluid collecting portion 28 through asecond collecting tube 26. The liquid collecting portion 28 is equippedwith a tank that accommodates the collected fluid 1 and the like. Thefluid 1 collected by the fluid collecting portion 28 may be, forexample, disposed or recycled by returning it to the fluid supplyportion 11 or the like after cleaning. In addition, a flow meter 27 thatmeasures the amount of collected fluid 1 (the amount of fluid collectedper a unit time) is provided in the middle of the second collecting tubebetween the gas/liquid separator 22 and the fluid collecting portion 28.The flow meter 27 constantly monitors the amount of the fluid collectedfrom the substrate P and outputs the result of the measurement to thecontrol device CONT. As described above, the liquid 1 on the substrate Pand the ambient gas are collected from the collecting nozzle 21. Byseparating the fluid 1 and ambient gas by the gas/fluid separator 22 andsending only the fluid composition to the flow meter 27, the flow meter27 can accurately measure the amount of fluid uncollected from thesubstrate P.

In addition, the exposure apparatus EX is equipped with a focusdetection system 56 that detects a position of a surface of thesubstrate P supported by the substrate stage PST. The focus detectionsystem 56 is equipped with a light projection portion 56A that projectsa detection luminous flux onto the substrate P from a diagonal directionthrough the fluid 1, and a light receiving portion 56B that receivesreflection light of the detection luminous flux reflected on thesubstrate P. The result of receiving light by the focus detection system56 (light receiving portion 56B) is output to the control device CONT.Based on the result of detection by the focus detection system 56, thecontrol device CONT can detect the positional information of the surfaceof the substrate P in the Z-axis direction. In addition, by projecting aplurality of luminous fluxes by the light projection portion 56A, theinclination information of the substrate P in the θX and θY directionsalso can be obtained.

In addition, as shown in a partial cross-sectional diagram in FIG. 6,the fluid supply mechanism 10 and the fluid collecting mechanism 20 areseparately supported with respect to the lens barrel support plate 8. Asa result, vibration generated at the fluid supply mechanism 10 and thefluid collecting mechanism 20 is hardly transferred to the projectionoptical system PL through the lens barrel support plate 8.

FIG. 8 is a plane diagram showing the positional relationship of thefluid supply mechanism 10, the fluid collecting mechanism 20, and theprojection region AR1 of the projection optical system PL. Theprojection region AR1 of the projection optical system PL is in arectangular shape (slit shape) that is long and thin and extends in theY-axis direction. Three supply nozzles 14A-14C are positioned on the +Xside, and two collecting nozzles 21A and 21B are positioned on the −Xside, so as to sandwich the projection region AR1 in the X-axisdirection, and the collecting nozzles 21A and 21B are connected to thevacuum system 25 via the collecting tube 24. Furthermore, at theposition at which the supply nozzles 14A-14C and the collecting nozzles21A and 21B are rotated substantially by 180°, the supply nozzles14A′-14C′ and collecting nozzles 21A′0 and 21B′ are positioned. Thesupply nozzles 14A-14C and the collecting nozzles 21A′ and 21B′ arearranged alternately in the Y-axis direction, and the supply nozzles14A′-14C′ and the collecting nozzles 21A and 21B are alternatelyarranged in the Y-axis direction. The supply nozzles 14A′-14C′ areconnected to the fluid supply portion 11 via the supply tube 15′, andthe collecting nozzles 21A′ and 21B′ are connected to the vacuum system25 via a collecting tube 24′. Similar to the supply tube 15, a flowmeter 12′ and a valve 13′ are provided in the middle of the supply tube15′. In addition, similar to the collecting tube 24, a gas/fluidseparator 22′ and a dryer 23′ are provided in the middle of thecollecting tube 24′.

Next, steps for exposing the pattern of the mask M onto the substrate Pusing the above-described exposure apparatus EX are described.

After loading the mask M on the mask stage MST and loading the substrateP onto the substrate stage PST, the control device CONT drives the fluidsupply portion 11 of the fluid supply mechanism 10 and supplies thepredetermined amount of the fluid 1 per unit time onto the substrate Pthrough the supply tube 15 and the supply nozzle 14. In addition, thecontrol device CONT drives the vacuum system 25 of the fluid collectingmechanism 20 in accordance with the supply of the fluid 1 by the fluidsupply mechanism 10, and collects the predetermined amount of the fluid1 per unit time through the collecting nozzle 21 and the collecting tube24. As a result, an immersion region AR2 for the fluid 1 is formedbetween the optical element 2 at the front end portion of the projectionoptical system PL and the substrate P (step of filling fluid). To formthe immersion region AR2, the control device CONT controls each of thefluid supply mechanism 10 and the fluid collecting mechanism 20 so as tomake the amount of the fluid supplied to the substrate P and the amountof fluid collected from the substrate P become substantially the sameamount. In addition, the control device CONT illuminates the mask M bythe exposure light EL using the illumination optical system IL, andprojects the image of the pattern on the mask M onto the substrate Pthrough the projection optical system PL and the fluid 1.

At a time of scan exposure, a portion of a pattern image on the mask Mis projected onto the projection region AR1. Synchronous to the mask Mmoving in the −X direction (or +X direction) at speed V with respect tothe projection optical system PL, the substrate P moves in the +Xdirection (or −X direction) at speed β·V (where β is a projectionmagnification) via the substrate stage PST. Then, after the completionof the exposure in one shot region, the next shot region is moved to ascan start position by the stepping of the substrate P, and the exposureprocess for each shot region is sequentially performed using astep-and-scan method. In this embodiment, the fluid 1 is set to flow inthe direction parallel to the direction of movement of the substrate P,that is, in the same direction as the direction of the movement of thesubstrate P.

In other words, when performing the scan exposure by moving thesubstrate P in the scan direction (−X direction) shown by an arrow Xa(see FIG. 8), supply and collection of the fluid 1 by the fluid supplymechanism 10 and the fluid collecting mechanism 20 are performed usingthe supply tube 15, the supply nozzle 14A-14C, the collecting tube 24,and the collecting nozzles 21A and 21B. That is, when the substrate Pmoves in the −X direction, the fluid 1 is supplied between theprojection optical system PL and substrate P using the supply nozzle 14(14A-14C), and the fluid 1 on the substrate P is collected by thecollecting nozzle 21 (21A and 21B) along with the ambient gas.Therefore, the fluid 1 flows in the −X direction so as to fill betweenthe optical element 2 at the front end portion of the projection opticalsystem PL and the substrate P.

On the other hand, when performing the scan exposure by moving thesubstrate P in the scan direction (+X direction) shown with an arrow Xb(see FIG. 8), supply and collection of the fluid 1 by the fluid supplymechanism 10 and the fluid collecting mechanism 20 are performed usingthe supply tube 15′, the supply nozzles 14A′-14C′, the collecting tube24′, and the collecting nozzles 21A′ and 21B′. That is, when thesubstrate P moves in the +X direction, the fluid 1 is supplied betweenthe projection optical system PL and substrate P using the supply nozzle14′ (14A′-14C′), and the fluid 1 on the substrate P is collected by thecollecting nozzle 21′ (21A′ and 21B′) along with the ambient gas.Therefore, the fluid 1 flows in the +X direction so as to fill betweenthe optical element 2 at the front end portion of the projection opticalsystem PL and the substrate P. In this case, the fluid 1 supplied viathe supply nozzle 14 flows as if it is pulled between the opticalelement 2 and the substrate P in accordance with the movement of thesubstrate P in the −X direction or +X direction. Therefore, the fluid 1can be supplied easily between the optical element 2 and the substrate Peven if the supply energy of the fluid supply mechanism 10 (fluid supplyportion 11) is small. Therefore, by switching the direction of the flowof the fluid 1 depending on the scan direction, the space between theoptical element 2 and the substrate P can be filled with the fluid 1even when the substrate P is scanned in either direction of the +Xdirection and the −X direction. Therefore, high resolution and widedepth of focus can be obtained.

During the exposure process, the result of measurement by the flow meter12 provided in the fluid supply mechanism 10 and the result of themeasurement by the flow meter 27 provided in the fluid collectingmechanism 20 are constantly output to the control device CONT. Thecontrol device CONT compares the result of measurement by the flow meter12, that is, the amount of fluid supplied on the substrate P by theliquid supply mechanism 10, and the result of measurement by the flowmeter 27, that is, the amount of fluid collected from the substrate P bythe liquid collecting mechanism 20, and controls the valve 13 of thefluid supply mechanism 10 based on the result of the comparison. Indetail, the control device CONT determines a difference between theamount of fluid supplied on the substrate P (the result of measurementby the flow meter 12) and the amount of fluid collected from thesubstrate P (the result of measurement by the flow meter 27), andcontrols the valve 13 based on whether the determined difference exceedsa predetermined tolerance (threshold value). As described above, sincethe control device CONT controls each of the fluid supply mechanism 10and the fluid collecting mechanism 20 so as to make the amount of thefluid supplied to the substrate P and the amount of fluid collected fromthe substrate P substantially the same, the above-described determineddifference becomes substantially zero under a condition in which thefluid supply operation by the fluid supply mechanism 10 and the fluidcollection operation by the fluid collecting mechanism 20 are normallyperformed.

If the determined difference is more than the tolerance, that is, if theamount of the fluid collected is extremely small compared to the amountof fluid supplied, the control device CONT determines, as a result ofthe malfunction of the collecting operation by the fluid collectingmechanism 20, that a sufficient amount of the fluid is not collected. Atthis time, the control device CONT determines that abnormalities, suchas malfunctions, occurred at the vacuum system 25 of the fluidcollecting mechanism 20, for example. In addition, to prevent a leakingof the fluid 1 due to the fact that the fluid 1 cannot be normallycollected by the fluid collecting mechanism 20, the control device CONTcloses the flow path of the supply tube 15 by operating the valve 13 ofthe fluid supply mechanism 10, and stops the supply of the fluid 1 tothe substrate P by the fluid supply mechanism 10. Accordingly, thecontrol device CONT compares the amount of fluid supplied to thesubstrate P from the fluid supply mechanism 10 and the amount of thefluid collected by the fluid collecting mechanism 20, detects theabnormality of the collecting operation of the fluid collectingmechanism 20 based on the result of the comparison, and stops the supplyof the fluid 1 to the substrate P when the fluid 1 is oversupplied orabnormalities are detected. In addition, the control device CONT maygenerate a warning via the above-described warning device K when theabnormality is detected. In addition, the control device CONT maydisplay the abnormality to a display device by providing the displaydevice to the above-described warning device K. Furthermore, byproviding a water leakage sensor at at least a part (e.g., gutter member72 or groove portion) of the collecting device 71, the abnormality canbe detected based on the result of the detection by the water leakagesensor.

At this time, the fluid 1 that has been supplied onto the substrate P isnot collected by the fluid collecting mechanism 20, as described in theabove first embodiment, but instead outflows directly from the substratestage PST or indirectly onto the upper surface 41A of the substratesupport plate 41 via the X guide stage 44. A part of the outflown fluidis collected by flowing into the gutter member 72. In addition, thefluid remaining on the support plate upper surface 41A can be collectedby flowing the fluid into the gutter member 72 by the control deviceCONT driving (an actuator of) the vibration actuation unit 9 to tilt thesubstrate support plate 41.

As described above, in this embodiment, by filling the optical pathbetween the optical element 2 and the substrate P with fluid 1, highresolution and large depth of focus can be obtained, and even when thefluid scatters or outflows from the substrate P for any reason,troubles, such as malfunction of the device and/or members, electricleakage, and/or rust/oxidation, are prevented beforehand by collectingthe fluid, allowing smooth execution of the exposure processes.

Some preferred embodiments according to this invention are describedabove with reference to the attached drawings. However, this inventionis not limited to these embodiments. One of ordinary skill in the artwould be able to achieve various modifications and corrections.

For example, in the above embodiments, a gutter member 72 is provided inthe vicinity of the substrate support plate 41 as a collecting portionof the collecting device 71. However, the invention is not limited tothis. As shown in FIG. 9, for example, by forming a groove portion 81 bya step portion 41B, which is formed lower than the substrate top surface41A, along the entire circumference of the edge of the substrate supportplate 41, and a wall member 80 provided on the side surface of thesubstrate support plate 41, the fluid scattered and outflown to thesubstrate support plate 41 is collected by the groove portion 81. Inthis case, it also is preferred that the fluid repellent treatment isperformed in the groove portion 81 to smoothly collect the fluid, andthat the step portion 41B is inclined.

Furthermore, as shown in FIG. 10, without using the wall member, thegroove portion 81 may be provided on the entire circumference of theouter circumference of the substrate support plate 41, and this grooveportion 81 may function as a collecting portion.

The groove portion 81 need not necessarily be provided on the entirecircumference of the substrate support plate 41. For example, two grooveportions 81 may be provided on the outer circumference of the substratesupport plate 41 in the X direction (scan direction), and two guttermembers 72 may be provided along the outer circumference of thesubstrate support plate 41 in the Y direction (non-scan direction).Accordingly, portions of the collecting devices 71 disclosed in theembodiment may be combined.

In addition, in the above embodiments, the description was made with theX guide stage 44 having a cross-section schematically in a U-shape.However, as shown in FIG. 11, it may be schematically in an H shape in across-sectional view. Because a large load is applied in the widthdirection (left-right direction in FIG. 11) by the air from the airbearing provided on the substrate stage PST, the sidewall 44C of the Xguide stage 44 is made in a shape symmetrical in the up-down directionby forming in the H shape, to prevent unbalanced load from being appliedto the X guide stage 44. In addition, the inclined surface 44A may beprovided only on the upper portion side. However, to prevent theunbalanced load, it is preferred that it be provided symmetrically onthe lower surface side as well.

Furthermore, in the above embodiments, the fluid remaining on thesubstrate upper surface 41A is removed by tilting the stage supportplate 41 using the vibration isolation unit 9. However, a structure inwhich the substrate upper surface 41A is made an inclined surface thatinclines with respect to the horizontal plane may also be used. In thiscase, since the position of the substrate surface in the Z-axisdirection changes due to the movement of the substrate stage PST, theposition of the surface of the substrate P should be corrected bydriving the position of the table portion PH in the Z-axis directiondepending on the position of the substrate stage PST.

Similarly, to make the removal of the fluid remaining on the tableportion PH smooth, the surface of the table portion PH may be made aninclined surface or processed with the fluid repellent treatment.

Moreover, when tilting the substrate support plate 41, and when thesurface of the table portion PH is made an inclined surface, it ispreferred to incline the substrate support plate 41 such that the sideon which members that are not supposed to contact the fluid, such asmovable mirrors and fiducial marks, are not provided on the lower side.

As described above, the fluid 1 according to the embodiments is composedof pure water. Advantages of using such a fluid are that it can beobtained in large amounts at semiconductor manufacturing facilities andthat there are no negative effects to the photoresist or the opticalelements (lens) on the substrate P. In addition, because pure water hasno negative effects to the environment, and because the amount ofimpurities is extremely low, it is expected to clean the surface of thesubstrate P and the surface of the optical elements provided on thefront end surface of the projection optical system PL.

The refractive index of pure water (water) with respect to the exposurelight EL having the wavelength of approximately 193 nm is about 1.44,when the ArF excimer laser light (wavelength: 193 nm) is used as thelight source for the exposure light EL. Therefore, high resolution isobtained by shortening the wavelength by 1/n, that is, approximately 139nm on the substrate P. In addition, since the depth of focus isincreased by approximately n times compared to that in the air, that is,approximate 1.44 times, when it is only sufficient to secure the depthof focus that is approximately the same as when using in the air, thenumeral aperture for the projection optical system PL can be increased,and thereby the resolution increases as well.

However, fluids other than water may be used. For example, if the lightsource for the exposure light EL is a F₂ laser, the F₂ laser light isnot transmitted in water. Thus, a fluid of a fluorine system, such asfluorine oil and perfluorinated polyether (PFPE), that can transmit theF₂ laser light may be used as the fluid 1. In addition, it is alsopossible to use, as the fluid 1, a material that has transmissivity withrespect to the exposure light EL, has high refractivity, and is stablewith respect to photoresist applied on the projection optical system PLand the surface of the substrate P (e.g., cedar oil).

In addition, in these embodiments, the optical element 2 is mounted onthe front end of the projection optical system PL. The optical elementmounted on the front end of the projection optical system PL can be anoptical plate used for adjusting the optical characteristics of theprojection optical system PL, such as aberrations (spherical aberration,coma etc.). Instead, it may be a parallel plate that can transmit theexposure light EL.

In each of the above-described embodiments, the shape of theabove-described nozzles is not particularly limited. For example, thesupply and collection of the fluid 1 may be performed by two pairs ofnozzles provided at the long sides of the projection region AR1. In thiscase, to allow the supply and collection of the fluid 1 to be performedin any one of the +X direction and the −X direction, arrangements may bemade by positioning the supply nozzles and the collection nozzles aboveand below.

For the substrate P in each of the above-described embodiments, not onlya semiconductor wafer for manufacturing semiconductor devices, but alsoglass substrates for manufacturing display devices, ceramic wafer formanufacturing thin-film magnetic heads, original plates formanufacturing masks and reticles (synthetic quartz and silicon wafer)used in an exposure device, may be used.

In the above-described embodiments, an exposure apparatus is provided inwhich the optical path between the projection optical system PL and thesubstrate P is locally filled with a fluid. However, this invention canbe used in an immersion exposure apparatus in which a stage that holds asubstrate to be exposed is moved in a fluid tank, as disclosed inJapanese Laid-Open Patent Application No. H06-124873, or an immersionexposure apparatus in which a fluid tank having a predetermined depth isformed on a stage and the substrate is held therein, as disclosed inJapanese Laid-Open Patent Application No. H10-303114.

As the exposure apparatus EX, in addition to the scan-type exposureapparatus (scanning stepper) using a step-and-scan method thatscan-exposes the pattern on the mask M by synchronously moving the maskM and the substrate P, a projection exposure apparatus (stepper) using astep-and-repeat method in which the pattern on the mask M is entirelyexposed in a state where the mask M and the substrate P are stationary,and the substrate P is sequentially stepped, may be used. In addition,this invention may be used in an exposure apparatus using astep-and-stitch method in which at least two patterns are partiallysuperimposingly transferred onto the substrate P.

In addition, this invention may be used in a twin-stage type exposureapparatus, which is equipped two wafer stages (substrate stages) and inwhich the two wafer stages are switched between an alignment positionand an exposure position, as disclosed in Japanese Laid-Open PatentApplication No. 2001-160530. In this case, the fluid supply portion 11and the fluid collecting portion 28 may be maintained driven when thetwo wafer stages are switched. This is because, as described above, thefluid 1 from the fluid supply portion 11 can be collected via thesubstrate support plate 41. As a result, the throughput for the twinstage type exposure device can be further increased.

As for the type of the exposure apparatus EX, the invention is notlimited to the exposure apparatus for manufacturing semiconductorelements that exposes semiconductor element patterns on the substrate P.It may be used for an exposure apparatus for manufacturing liquidcrystal display elements or for manufacturing displays, as well as anexposure apparatus for manufacturing thin-film magnetic heads, imageshooting elements (CCD), reticles or masks.

When using a linear motor for the substrate stage PST or the mask stageMST (see, e.g., U.S. Pat. No. 5,623,853 or U.S. Pat. No. 5,528,118), itis preferred to use either an air flow type that uses an air bearing asa type of flowing the stages with respect to the support plate, or amagnetic flow type that uses Lorentz force. In addition, each of thestages PST and MST may be of a type that moves along a guide, or eachmay be of a guideless type that provides no guides.

For the drive mechanism for each of the stages PST and MST, a flat motormay be used that drives each of the stages PST and MST using magneticforce by facing a magnetic unit in which magnets are two-dimensionallypositioned, and an armature unit in which coils are two-dimensionallypositioned. In this case, either one of the magnetic unit and thearmature unit should be connected to the stages PST and MST, and theother one of the magnetic unit and the armature unit should be providedon the moving surface side of the stages PST and MST.

The reaction force generated by the movement of the substrate stage PSTmay be transmitted mechanically to the floor (ground) using a framemember, as described in Japanese Laid-Open Patent Application No.H08-166475 (U.S. Pat. No. 5,528,118), so as not to transfer it to theprojection optical system PL. The reaction force generated by themovement of the mask stage MST may be transmitted mechanically to thefloor (ground) using a frame member, as described in Japanese Laid-OpenApplication No. H8-330224 (U.S. Ser. No. 08/416,558), so as not totransfer it to the projection optical system PL.

The exposure apparatus EX of this embodiment is manufactured byassembling various subsystems, including each structural elementdescribed in this application, so as to maintain predeterminedmechanical accuracy, electrical accuracy, and optical accuracy. Toassure these various accuracies, adjustments are performed before andafter the assembly by adjusting the various optical systems to achievethe optical accuracy, by adjusting the various mechanical systems toachieve the mechanical accuracy, and by adjusting the various electricalsystems to achieve the electrical accuracy. The process for assembling,from various subsystems, the exposure apparatus includes mechanicalconnections, wiring connections for electric circuits, ductingconnections for air pressure circuits, and the like, that are performedfor the various subsystems. Before the assembly process of these varioussubsystems to form the exposure device, individual assembly processesfor each subsystem are performed. After completing the assemblyprocesses of the various subsystems to form the exposure device, theentire adjustments are conducted to assure various accuracies as theexposure apparatus as a whole. In addition, it is preferred that themanufacturing of the exposure apparatus be performed in a clean room inwhich the temperature and cleanliness are controlled.

As shown in FIG. 12, a micro device, such as a semiconductor device, ismanufactured through a step 201 of designing functions and performanceof the micro device, a step 202 of manufacturing a reticle (s) based onthe design step, a step 203 of manufacturing a substrate that is a basematerial for the device, a step 204 of processing the substrate where apattern of the reticle is exposed on the substrate by the exposureapparatus EX of the above-described embodiments, a step 205 ofassembling the device (including dicing process, bonding process, andpackaging process), and an inspection step 206.

While the invention has been described with reference to preferredembodiments thereof, it is to be understood that the invention is notlimited to the preferred embodiments or constructions. To the contrary,the invention is intended to cover various modifications and equivalentarrangements. In addition, while the various elements of the preferredembodiments are shown in various combinations and configurations, thatare exemplary, other combinations and configurations, including more,less or only a single element, are also within the spirit and scope ofthe invention.

1. A stage device comprising: a movable body that holds an object towhich liquid is supplied; a supporting plate which movably supports themovable body, the movable body being movable linearly relative to thesupporting plate; and a collection device arranged to collect liquidthat has been discharged to the supporting plate, the collection deviceincluding a collection portion arranged along an outer circumference ofthe supporting plate.
 2. The stage device of claim 1, wherein thecollection portion surrounds a guide surface of the supporting plate bybeing arranged adjacent the outer circumference of the supporting plate.3. The stage device of claim 1, wherein the collection portion includesan inclined portion which conveys the liquid in a downward directionfrom a surface of the supporting plate.
 4. The stage device of claim 1,wherein the collection portion is liquid repellant.
 5. The stage deviceof claim 1, wherein the supporting plate is liquid repellant.
 6. Thestage device of claim 1, further comprising a stage structural bodyarranged above the supporting plate, the stage structural body isprovided with an inclined portion which conveys the liquid in a downwarddirection from the object.
 7. The stage device of claim 6, wherein thestage structural body is liquid repellant.
 8. The stage device of claim1, further comprising a spraying device which sprays fluid on a surfaceof the supporting plate to facilitate removal of the liquid remaining onthe surface of the supporting plate.
 9. An exposure apparatus whichexposes, by a projection optical system, a pattern of a mask onto aphotosensitive substrate which is held by a substrate stage, theexposure apparatus comprising: the stage device of claim 1, which isused as the substrate stage, such that the photosensitive substrate isthe object; and wherein an image of the pattern is projected onto thephotosensitive substrate through the liquid which is located between anend portion of the projection optical system and the photosensitivesubstrate.
 10. The stage device of claim 1, wherein the collectionportion includes a groove portion formed in the supporting plate.
 11. Astage device comprising: a movable body that holds an object to whichliquid is supplied; a supporting plate which movably supports themovable body; a collection device arranged to collect liquid that hasbeen discharged to the supporting plate; and a stage structural bodyarranged above the supporting plate, the stage structural body isprovided with an inclined portion which conveys the liquid in a downwarddirection from the object, wherein a through hole which passes throughthe stage structural body is formed in a low end portion of the inclinedportion.
 12. An exposure apparatus which exposes, by a projectionoptical system, a pattern of a mask onto a photosensitive substratewhich is held by a substrate stage, the exposure apparatus comprising:the stage device of claim 11, which is used as the substrate stage, suchthat the photosensitive substrate is the object; and wherein an image ofthe pattern is projected onto the photosensitive substrate through theliquid which is located between an end portion of the projection opticalsystem and the photosensitive substrate.
 13. A stage device comprising:a movable body that holds an object to which liquid is supplied; asupporting plate which movably supports the movable body; a collectiondevice arranged to collect liquid that has been discharged to thesupporting plate; and an actuator which inclines the supporting plate tofacilitate removal of the liquid remaining on a surface of thesupporting plate.
 14. An exposure apparatus which exposes, by aprojection optical system, a pattern of a mask onto a photosensitivesubstrate which is held by a substrate stage, the exposure apparatuscomprising: the stage device of claim 13, which is used as the substratestage, such that the photosensitive substrate is the object; and whereinan image of the pattern is projected onto the photosensitive substratethrough the liquid which is located between an end portion of theprojection optical system and the photosensitive substrate.
 15. A stagedevice comprising: a movable body that holds an object to which liquidis supplied; a supporting plate which movably supports the movable body;a collection device arranged to collect liquid that has been dischargedto the supporting plate; and a stage structural body arranged above thesupporting plate, the stage structural body is provided with an inclinedportion which conveys the liquid in a downward direction from theobject, the movable body being movable linearly over the stagestructural body.
 16. The stage device of claim 15, wherein thecollection device includes a collection portion arranged along an outercircumference of the supporting plate.
 17. The stage device of claim 16,wherein the collection portion includes an inclined portion whichconveys the liquid in a downward direction from a surface of thesupporting plate.
 18. The stage device of claim 16, wherein thecollection portion is liquid repellant.
 19. The stage device of claim15, wherein the supporting plate is liquid repellant.
 20. The stagedevice of claim 15, wherein a through hole which passes through thestage structural body is formed in a low end portion of the inclinedportion.
 21. The stage device of claim 15, wherein the stage structuralbody is liquid repellant.
 22. The stage device of claim 15, furthercomprising an actuator which inclines the supporting plate to facilitateremoval of the liquid remaining on a surface of the supporting plate.23. The stage device of claim 15, further comprising a spraying devicewhich sprays fluid on a surface of the supporting plate to facilitateremoval of the liquid remaining on the surface of the supporting plate.24. An exposure apparatus which exposes, by a projection optical system,a pattern of a mask onto a photosensitive substrate which is held by asubstrate stage, the exposure apparatus comprising: the stage device ofclaim 15, which is used as the substrate stage, such that thephotosensitive substrate is the object; and wherein an image of thepattern is projected onto the photosensitive substrate through theliquid which is located between an end portion of the projection opticalsystem and the photosensitive substrate.
 25. The stage device of claim15, wherein the collection device includes a groove portion formed inthe supporting plate.